It is known to provide wireless power transfer, such as for wireless charging, by near field coupling from a transmitter coil to a receiver coil over distances ranging from about 1 cm to several meters. Efforts have been made to improve the efficiency of wireless power transfer systems by, for example, optimizing the shape of the coil used to transfer the power, adopting soft switching technology, using Litz wire, and employing new resonant tank structures. Such an approach is described, for example, in U.S. patent application Ser. No. 14/143,505; Filed Dec. 30, 2013, entitled METHODS, CIRCUITS AND ARTICLES OF MANUFACTURE FOR CONFIGURING DC OUTPUT FILTER CIRCUITS, the entire disclosure of which is incorporated herein by reference.
It is also known to provide wireless power transfer using inductive coupling from a primary side converter to a secondary side converter.